Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a display screen or portion thereof withtransitional graphical user interface showing the first image of asequence according to our new design;

FIG. 2 is a second image thereof; and,

FIG. 3 is a third image thereof.

The appearance of the transitional image transitions sequentiallybetween the images shown in FIGS. 1-3. The process or period in whichone image transitions to another image forms no part of the claimeddesign.

The dot-dash broken line perimeter illustrates a display screen orportion thereof and forms no part of the claimed design.

The portions shown in a pattern of stipple illustrate areas ofcontrasting appearance.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.